yaml_reader.cpp is for manipulaing lattices direcly in C++. yaml_c_wrapper.cpp wraps YAML::Node into C objects so they can be part of a shared object library to interface with other languages
First install yaml-cpp by running
macOS:
brew install yaml-cpp
Linux:
sudo apt-get install libyaml-cpp-dev
Windows:
choco install yaml-cpp
Manual Install:
git clone https://github.com/jbeder/yaml-cpp.git
cd yaml-cpp/src
mkdir build && cd build
cmake ..
cmake --build .
cmake --install .
Next, in pals-cpp, run
mkdir build && cd build
cmake .. -DYAML_BUILD_SHARED_LIBS=ON
make